The Puerto Rico Trench is the deepest place
in the Atlantic Ocean, plunging more than
five miles below sea level. Lying about 75
miles north of the island of Puerto Rico, this long, narrow
gash in the seafloor extends to the east for
nearly 1,100 miles. The region remains
poorly understood, largely because its
tremendous depth makes it difficult to study.
Even remotely operated vehicles (ROVs) and
other deep-sea research tools have not been
able to reach the bottom of the trench, yet
recent exploration cruises and mapping
projects have begun to unravel the mystery.
The Trench began to form about 70 million
years ago, as the North American and
Caribbean tectonic plates started to grind
past each other along the Bunce Fault system
named for a pioneering geophysicist, Dr.
Elizabeth Bunce. This fault system is similar
to the San Andreas Fault in California.
Because Puerto Rico and the U.S. Virgin
Islands lie on this active plate boundary,
tsunami-causing earthquakes and submarine
landslides are a real threat to nearly four
million local residents.